bitPimps.lixlink.com

the thing ingraved on the back of the controller(ms) that looks like a microsizers motor with the gear off and under the gear it says in with a triangle pointing to a hole
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BIT PIMPS STREET RACING

Some motors don't come with the gear already assembled onto the motor shaft. The controller is designed to help you with this, when the gear is placed in the hole it will hold it steady for you while you slide in the shaft. It also spaces the gear at the correct length too.